Research On High-frame Rate Image Capture And Transmission System

With the advent of high-frame rate digital cameras, the amount of video image data is bigger and bigger, so that the various technical indicators of data acquisition, transmission and processing are put forward higher requirements. High-frame rate cameras are of high frame frequency output and large data capacity. In order to ensure rapid and steady acquisition and transmission of image data, this paper designs the high-frame rate image capture and transmission system.The rapid development and updating of Field Programmable Gate Array(FPGA) make it possible that complicated, high-speed images can be processed and operated. The Camera Link standard defines a digital camera capture interface, which is a high-speed serial communication protocol. It provides a simple, flexible connectivity for high-speed digital camera and has been widely used in image capture. PCI Express is the latest high-speed serial I/O bus. PCI Expresss bus can be applied to various types of computers and peripherals for interconnect communication and it is the perfect transmission interface for embedded systems. The IEEE 1394 b serial bus is developed on the basis of the IEEE 1394 a and it can undertake high-speed, long-distance transmission. The IEEE 1394 b serial bus is widely used in many fields.This paper describes the technology of the current advanced Camera Link, PCI Expresss and IEEE 1394 b bus. And according to these technical standards, it designes a high-frame rate image capture and transmission system based on FPGA platform. The system uses Altera’s FPGA chip as the main core processing unit and uses Verilog language to realize internal logic of FPGA. Then the image data are captured by Camera Link interface, stored in the DDR2 SDRAM via asynchronous FIFO buffer module and transfered to the host computer through the PCI Express interface. In addition, this paper introduces the transmission scheme of 1394 b based on PCI Experss transmission module, which can realize long-distance and high-speed image data transmission.This paper is divided into two parts to describe the image capture and transmission system: the image capture section and the data transmission section. For the image capture part, it introduces the design of hardware circuit and software program based on Camera Link interface, to realize the function of image data receiving and cache processing, the serial communication between the camera and FPGA as well as the control of camera interface. For the image transmission part, the paper describes the PCIE transmission module and 1394 b transmission module. First, based on the acquaintance of the PCIE protocol specification, the paper studies the method of generating PCIE IP hard-core and the application logic design of the transmission part, realizing the function of the PCIE layered protocols and and details the implementation of PCIE bus data transmission.Then on the basis of the PCIE bus interface, combined with the physical layer and link layer chip of 1394 b, the paper tells IEEE 1394 b chip circuit design and programming of FPGA’s NIOS II.And it designs the scheme of long-distance transmission through 1394 b bus.In conclusion, this paper completes the design of high-frame rate image capture and transmission system based on FPGA and validates the capture and transmission function through the simulation test of the system.